Sheet processing apparatus, finishing apparatus and sheet guide method

ABSTRACT

A sheet processing apparatus of an embodiment includes a spring member which supports a support leg provided on an end bottom of a finishing apparatus at a side of an image forming apparatus and is extendable in a height direction, a sheet feed port which is formed in the finishing apparatus to be opposite to a sheet discharge port of the image forming apparatus and has a width wider than a width of the sheet discharge port in the height direction, sheet discharge guides which are arranged to be opposite to each other at an exit of the sheet discharge port and sandwich a conveyance path of the sheet in the image forming apparatus, sheet feed guides which are arranged to be opposite to each other at an inlet of the sheet feed port and sandwich a conveyance path of the sheet in the finishing apparatus, electromagnets provided at ends of the sheet feed guides at a side of the sheet feed port, and magnetic members which are rotatably provided to ends of the sheet discharge guides at a side of the sheet discharge port and are attracted by the electromagnets.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the priority of U.S. Provisional Application No. 61/187,192, filed on Jun. 15, 2009, U.S. Provisional Application No. 61/226,625, filed on Jul. 17, 2009, the entire contents of which are incorporated herein by reference.

FIELD

An embodiment described below relates to a sheet processing apparatus for guiding a sheet from an image forming apparatus to a finishing apparatus, and the finishing apparatus for finishing the sheet discharged from the image forming apparatus. Besides, an embodiment relates to a sheet guide method for guiding a sheet from the image forming apparatus to the finishing apparatus.

BACKGROUND

In recent years, an image forming apparatus (for example, an MFP) is provided with a finishing apparatus adjacent to the latter stage of the MFP in order to finish a sheet after image formation. The finishing apparatus is called a finisher, and the finisher staples the sheet sent from the MFP or forms a punch hole in the sheet and discharges it through a discharge port to a storage tray.

When the finishing apparatus is attached to the latter stage of the image forming apparatus, designed so that the height of a sheet discharge port of the image forming apparatus is equal to the height of a sheet feed port of the finishing apparatus. However, when a floor surface on which the image forming apparatus and the finishing apparatus are placed is not flat, takes time to adjust the heights of the sheet discharge port and the sheet feed port. When the heights of the sheet discharge port and the sheet feed port are different from each other, the delivery of the sheet from the image forming apparatus to the finishing apparatus becomes incomplete, and a jam may occur.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an overall structural view of a sheet processing apparatus of an embodiment.

FIG. 2 is a structural view showing an image forming apparatus (MFP) and a finishing apparatus (finisher) separately.

FIG. 3 is an explanatory view showing a state where the heights of floor surfaces on which the MFP and the finisher are placed are different from each other.

FIG. 4 is another explanatory view showing a state where the heights of the floor surfaces on which the MFP and the finisher are placed are different from each other.

FIG. 5 is a structural view showing the MFP and the finisher provided with a guide mechanism.

FIG. 6 is an enlarged structural view showing the guide mechanism.

FIG. 7 is an explanatory view showing the movement of the guide mechanism at the time of power-on.

FIG. 8 is a perspective view showing the principal part of the guide mechanism.

FIG. 9 is an explanatory view showing the operation of the guide mechanism in a state where the floor surface on which the MFP is placed is lower than the floor surface on which the finisher is placed.

FIG. 10 is an explanatory view showing the operation of the guide mechanism in a state where the floor surface on which the MFP is placed is higher than the floor surface on which the finisher is placed.

FIG. 11 is a block diagram showing a control system of the MFP and the finisher.

DETAILED DESCRIPTION

A sheet processing apparatus of an embodiment described below is for guiding a sheet from an image forming apparatus to a finishing apparatus, and includes a support leg provided on an end bottom of the finishing apparatus at a side of the image forming apparatus, a spring member to support the support leg and extendable in a height direction, a sheet feed port which is formed in the finishing apparatus to be opposite to a sheet discharge port of the image forming apparatus and has a width wider than a width of the sheet discharge port in the height direction, sheet discharge guides which are arranged to be opposite to each other at an exit of the sheet discharge port and sandwich a conveyance path of the sheet in the image forming apparatus, sheet feed guides which are arranged to be opposite to each other at an inlet of the sheet feed port and sandwich a conveyance path of the sheet in the finishing apparatus, electromagnets provided at ends of the sheet feed guides at a side of the sheet feed port, magnetic members which are rotatably provided to ends of the sheet discharge guides at a side of the sheet discharge port and are attracted by the electromagnets, and a control section which drives the electromagnets in a state where the image forming apparatus is connected to the finishing apparatus, and causes the electromagnets to attract the magnetic members to provide a taper-shaped expansion.

Hereinafter, a sheet processing apparatus of an embodiment will be described in detail with reference to the drawings. Incidentally, the same portion in the respective drawings is denoted by the same reference numeral.

In FIG. 1, an image forming apparatus 10 is, for example, an MFP (Multi-Function Peripherals) as a compound machine, a printer, a copying machine or the like. A finishing apparatus 20 is disposed adjacently to the image forming apparatus 10. A sheet on which an image is formed by the image forming apparatus 10 is conveyed to the finishing apparatus 20.

The finishing apparatus 20 includes, for example, a stapler (finishing section) to staple plural sheets supplied from the image forming apparatus 10. Hereinafter, the finishing apparatus 20 will be referred to as the finisher 20. Besides, a description will be made while the MFP is used as an example of the image forming apparatus 10.

A document table is provided at an upper part of a main body 11 of the MFP 10, and an auto document feeder (ADF) 12 is openably and closably provided on the document table. Besides, an operation panel 13 is provided at the upper part of the main body 11. The operation panel 13 includes an operation section 14 composed of various keys and a touch panel type display section 15.

A scanner section 16 is provided at the lower part of the ADF 12 in the main body 11. The scanner section 16 reads a document sent by the ADF 12 or a document placed on the document table, and generates image data. A printer section 17 is provided at the center part in the main body 11, and plural cassettes 18 to contain various sizes of sheets are provided at the lower part of the main body 11.

The printer section 17 includes a photoconductive drum, a laser and the like, processes the image data read by the scanner section 16 or image data created by a PC (Personal Computer) or the like and forms an image on a sheet. The printer section 17 scans and exposes the surface of the photoconductive drum by a laser beam from the laser, and forms an electrostatic latent image on the photoconductive drum. A charging unit, a developing unit, a transfer unit and the like are disposed around the photoconductive drum, the electrostatic latent image on the photoconductive drum is developed by the developing unit, and a toner image is formed on the photoconductive drum. The toner image is transferred to the sheet by the transfer unit. The structure of the printer section 17 is not limited to the foregoing example, but various systems are used.

The sheet on which the image is formed by the printer section 17 passes through a first conveyance path 41 and is discharged to a storage tray 43. Alternatively, the sheet passes through a second conveyance path 42 and is discharged to the finisher 20 by a sheet discharge roller 19. The first conveyance path 41 and the second conveyance path 42 are disposed in parallel in the height direction, and constitute a sheet conveyance path to convey a sheet subjected to image formation by the printer section 17. When the sheet S is not finished, the sheet is conveyed to the storage tray 43 through the conveyance path 41. When the sheet S is finished, the sheet is conveyed to the finisher 20 through the conveyance path 42.

The finisher 20 is for stapling the sheet, and includes a standby tray 21, a processing tray 22 and a stapler 23. The sheet S is received by an inlet roller 24 provided at a carry-in entrance of the finisher 20. The inlet roller 29 includes an upper roller and a lower roller and is driven by a motor.

A sheet feed roller 25 is provided downstream of the inlet roller 24, and the sheet S received by the inlet roller 24 is sent to the standby tray 21 through the sheet feed roller 25. The sheet feed roller 25 includes an upper roller and a lower roller and is driven by a motor. The processing tray 22 for stacking the sheets dropped from the standby tray 21 is disposed below the standby tray 21.

The standby tray 21 stacks the sheet S and has an openable structure. When a specified number of sheets S are stored, the standby tray 21 is opened, and the sheets S are dropped to the processing tray 22 by their own weight or the operation of a drop assistant member to forcibly drop. The processing tray 22 supports the sheet S in the period in which the stapler 23 staples the sheet S.

The sheet dropped to the processing tray 22 is guided to the stapler 23 by a roller 26, and the stapler 23 staples the sheet S. The roller 26 is driven by a motor, and rotation is reversed between when the roller 26 guides the sheet S to the stapler 23 and when the stapled sheet S is discharged.

When stapling is performed, the plural sheets S dropped from the standby tray 21 to the processing tray are aligned in the longitudinal direction as the conveyance direction, and are aligned in the lateral direction perpendicular to the conveyance direction and are stapled. A lateral alignment plate 27 is provided to align the sheets S in the lateral direction. The lateral alignment plate 27 performs the lateral alignment and sorting of the sheets S.

Besides, in order to assist the sheet S in dropping to the processing tray 22, a rotatable paddle 28 is provided at the position where the trailing edge of the sheet S drops. The paddle 28 is attached to a rotation shaft, slaps the sheet S dropped from the standby tray 21 onto the processing tray 22, and sends the sheet S in the direction to the stapler 23.

A stopper 29 to regulate the position of the trailing edge of the sheet S is provided at the end of the processing tray 22 at the stapler 23 side. Besides, a conveyance belt 30 is provided in order to convey the sorted or stapled sheets S to the storage tray 51. The conveyance belt 30 is stretched between pulleys 31 and 32, and a pawl member 30 a to hook and send the trailing edge of the sheet S is attached to the conveyance belt 30. A mechanism to rotate the pulleys 31 and 32 is omitted.

The conveyance belt 30 is rotated in an arrow t direction, so that the sheet S is discharged from a discharge port 33 to a storage tray 51. The storage tray 51 is moved up and down by a motor and receives the sheet S. The conveyance belt 30 and the pawl member 30 a guide the stapled sheet S to the discharge port 33.

Besides, when the sheet S stacked on the standby tray 21 is discharged to the storage tray 51 without stapling, the sheet S is not dropped to the processing tray 22 but is discharged by the rotation roller 34. Besides, the sheet S not required to be stapled can be discharged also to a fixed tray 52. A conveyance path is provided to guide the sheet S to the fixed tray 52. An assist arm 35 is swingably attached to an attachment shaft of the upper roller of the sheet feed roller 25. The assist arm 35 protrudes to the discharge side of the sheet feed roller 25, and presses the sheet to the standby tray 21 so that the trailing edge side of the sheet S discharged from the sheet feed roller 25 does not rise.

A leg 44 and a castor 45 are attached to the bottom of the MFP 10, and a castor 53 and a castor 54 are attached to the bottom of the finisher 20. The castors 53 and 54 are support legs to support the finisher 20. The castor 53 attached at the position close to the MFP 10 is supported by a spring 55, and the spring 55 is extendable in the height direction. Besides, a projection 46 as an index used when the MFP 10 and the finisher 20 are connected to each other is provided at the upper end of the MFP 10 at the finisher side, and the projection 46 is inserted into a reception port 56 of the finisher 20 so that the MFP 10 and the finisher 20 are connected.

When both the MFP 10 and the finisher 20 are independent type apparatuses, when the floor surface on which they are placed is uneven or there is a variation between both the apparatuses, the MFP 10 and the finisher 20 can not be well connected, the conveyance of the sheet can not be well performed, and a jam can occur.

In the embodiment, even if the floor surface on which the MFP 10 and the finisher 20 are placed is uneven or has a step, the spring 55 attached to the castor 53 can absorb the difference in placement height.

FIG. 2 shows a state where the MFP 10 and the finisher 20 are separated from each other. Incidentally, the structure of the finisher 20 is simplified and shown. When the floor surface on which the MFP 10 and the finisher 20 are placed is flat, the projection 46 is smoothly inserted into the reception port 56 and the connection can be performed. The height of the sheet discharge port of the sheet discharge roller 19 becomes equal to the height of the sheet feed port of the inlet roller 24, and the sheet can be delivered.

On the other hand, a description will be made to a case where there is a step between the floor surfaces on which the MFP 10 and the finisher 20 are placed. FIG. 3 shows a state where the floor surface on which the MFP 10 is placed is slightly lower than the floor surface on which the finisher 20 is placed. In the example of FIG. 3, when the projection 46 is inserted into the reception port 56, the spring 55 to support the castor 53 is contracted, and the height position of the castor 53 rises. Thus, the height of the sheet discharge port of the sheet discharge roller 19 becomes equal to the height of the sheet feed port of the inlet roller 24, and the step can be absorbed.

FIG. 4 shows a state where the floor surface on which the MFP 10 is placed is slightly higher than the floor surface on which the finisher 20 is placed. In the example of FIG. 4, when the projection 46 is inserted into the reception port 56, the spring 55 to support the castor 53 is extended, and the height position of the castor 53 is lowered. Thus, the height of the sheet discharge port of the sheet discharge roller 19 becomes equal to the height of the sheet discharge port of the inlet roller 24.

That is, in the finisher 20, in accordance with the height reference of the index (projection 46), the castor 53 moves up and down according to the step (difference between the height positions of the floor surfaces of placement). Thus, the heights of the sheet discharge port and the sheet feed port can be made coincident with each other. Incidentally, the castor 54 may also be supported by a spring 55. The finisher 20 can be placed horizontally on the floor surface by supporting both the castors 53 and 54 by the springs 55.

Also conceivable that the spring 55 is attached to the MFP 10 and the castor 45 is supported by the spring 55. However, since the weight of the MFP 10 is higher than the weight of the finisher 20, necessary to increase the force of the spring. Accordingly, when the castor 53 of the finisher 20 is supported by the spring 55, the force of the spring 55 maybe low, and the MFP 10 and the finisher 20 are more easily connected.

FIG. 5 is a structural view showing the MFP 10 and the finisher 20 which are provided with a guide mechanism 60 for smoothly delivering the sheet S from the sheet discharge roller 19 of the MFP 10 to the inlet roller 24 of the finisher 20. FIG. 5 shows a state where the MFP 10 and the finisher 20 are separated from each other. The guide mechanism 60 is provided in connecting sections of the MFP 10 and the finisher 20.

FIG. 6 is an enlarged structural view of the guide mechanism 60. The MFP 10 is provided with a sheet discharge port 47 at the finisher 20 side, and the finisher 20 is provided with a sheet feed port 57 opposite to the sheet discharge port 47. The sheet discharge port 57 has the width wider than the width of the sheet discharge port 47 in the height direction.

The sheet discharge roller 19 of the MFP 10 includes an upper roller 19A and a lower roller 19B, and sheet discharge guides 61A and 61B are provided at an exit portion of the sheet discharge port 47. The sheet discharge guides 61A and 61B are arranged to be parallel and opposite to each other so as to sandwich the conveyance path of the sheet S. One ends of link plates 62A and 62B are rotatably attached to ends of the sheet discharge guides 61A and 61B at the sheet discharge port 47 side. Magnetic members 63A and 63B such as iron are rotatably attached to the other ends of the link plates 62A and 62B.

On the other hand, the inlet roller 24 of the finisher 20 includes an upper roller 24A and a lower roller 24B, and sheet feed guides 64A and 64B are provided at an inlet portion of the sheet feed port 57. The sheet feed guides 69A and 64B are arranged to be parallel and opposite to each other so as to sandwich the conveyance path of the sheet S. Electromagnets 65A and 65B are attached to ends of the sheet feed guides 64A and 64B at the sheet feed port 57 side so as to be opposite to the magnetic members 63A and 63B.

The electromagnets 65A and 65B respectively include, for example, flat-shaped print coils, and generate magnetic fields to attract the magnetic members 63A and 63B by causing current to flow through the print coils.

The link plates 62A and 62B and the magnetic members 63A and 63B do not rotate at the time of power-off, and extend linearly to be parallel to the sheet conveyance path as shown in FIG. 6. At the time of power-on, the electromagnets 65A and 65B are excited, the electromagnets 65A and 65B respectively attract the opposite magnetic members 63A and 63B, and the link plates 62A and 62B rotate like a crank while the ends of the sheet discharge guides 61A and 61B are made fulcrums.

FIG. 7 shows the operation of the guide mechanism 60 when the power is turned on in the state where the MFP 10 and the finisher 20 are connected to each other. When the power is turned on, the electromagnets 65A and 65B are excited, the electromagnets 65A and 65B attract the opposite magnetic members 63A and 63B, and the link plates 62A and 62B rotate like a crank. When the magnetic members 63A and 63B are attracted by the electromagnets 65A and 65B, the upper and lower parts of the Sheet conveyance path expand to form a taper shape.

FIG. 7 shows the state where the height of the sheet discharge port of the MFP 10 is coincident with the height of the sheet feed port of the finisher 20, and the sheet S conveyed by the sheet discharge roller 19 is straightly supplied to the inlet roller 24. For convenience, in FIG. 7, the sheet discharge port 47 and the sheet feed port 57 are not illustrated.

When the interval between the sheet discharge guides 61A and 61B is L1, and the interval between the sheet feed guides 64A and 64B is L2, L1<L2 is established. That is, since the interval L2 between the sheet feed guides 64A and 64B is made wide, even if there is a step on the floor surface on which the MFP 10 and the finisher 20 are placed, the sheet S discharged from the MFP 10 can be fed to the finisher 20 without collision.

Incidentally, the sheet feed guides 64A and 64B are provided with taper sections 66A and 66B in front of the inlet roller 24. The sheet S can be guided to the inlet roller 24 by the taper sections 66A and 66B, and the occurrence of a jam can be more certainly prevented.

FIG. 8 is a perspective view showing the principal part of the guide mechanism 60. In FIG. 8, the sheet discharge guides 61A and 61B are arranged in parallel and at the interval L1, and the sheet S is conveyed in an arrow direction between the sheet discharge guides 61A and 61B. The upper roller 19A and the lower roller 19B of the sheet discharge roller 19 are arranged at portions of slits 67 formed in the sheet discharge guides 61A and 61B, and the upper roller 19A and the lower roller 19B are opposite to and contact each other.

The sheet feed guides 64A and 64B are arranged in parallel and at the interval L2, the upper roller 24A and the lower roller 24B of the inlet roller 24 are arranged in portions of slits 68 formed in the sheet feed guides 64A and 64B, and the upper roller 24A and the lower roller 24B are opposite to and contact each other. One ends of the link plates 62A and 62B are rotatably attached to the ends of the sheet discharge guides 61A and 61B, and the magnetic members 63A and 63B are rotatably attached to the other ends of the link plates 62A and 62B. The electromagnets 65A and 65B are respectively attached to the ends of the sheet feed guides 64A and 64B to be opposite to the magnetic members 63A and 63B.

When power is applied to the electromagnets 65A and 65B, the electromagnets 65A and 65B respectively attract the opposite magnetic members 63A and 63B, and the link plates 62A and 62B rotate like a crank while the ends of the sheet discharge guides 61A and 61B are made fulcrums. In FIG. 8, although each of the electromagnets 65A and 65B and the link plates 62A and 62B is composed of one piece, the respective one may be divided into plural pieces in a direction perpendicular to the conveyance direction of the sheet S.

FIG. 9 and FIG. 10 are explanatory view showing the operation of the guide mechanism 60 when there is an unevenness or a step on the floor surface on which the MFP 10 and the finisher 20 are placed.

FIG. 9 shows a state where the floor surface on which the MFP 10 is placed is slightly lower than the floor surface on which the finisher 20 is placed. In the example of FIG. 9, when power is applied to the electromagnets 65A and 65B, the electromagnet 65A and 65B respectively attract the opposite magnetic members 63A and 63B. However, since the height of the electromagnet 65A is high, the rotation angle of the link plate 62A is larger than the rotation angle of the link plate 62B. The sheet S conveyed by the sheet discharge roller 19 is supplied to the inlet roller 24.

FIG. 10 shows a state where the floor surface on which the MFP 10 is placed is slightly higher than the floor surface on which the finisher 20 is placed. In the example of FIG. 10, when power is applied to the electromagnets 65A and 65B, the electromagnets 65A and 65B respectively attract the opposite magnetic members 63A and 63B. However, since the position of the electromagnet 65B is low, the rotation angle of the link plate 62B is larger than the rotation angle of the link plate 62A. The sheet S conveyed by the sheet discharge roller 19 is supplied to the inlet roller 24.

As is understood from FIG. 9 and FIG. 10, since the interval L2 between the sheet feed guides 64A and 64B is made wider than the interval L1 between the sheet discharge guides 61A and 61B, even if there is a step, the sheet S discharged from the MFP 10 can be fed to the finisher 20 without collision. Accordingly, the sheet S can be smoothly conveyed from the MFP 10 to the finisher 20. Besides, when both the spring 55 to support the castor 53 and the guide mechanism 60 are used, the connection between the MFP 10 and the finisher 20 can be more stabilized.

FIG. 11 is a block diagram showing a control system of the MFP 10 and the finisher 20.

In FIG. 11, a main control section 101 includes a CPU 102, a ROM 103 and a RAM 104, and the CPU 102 controls the MFP 10 in accordance with a control program stored in the ROM 103. The main control section 101 controls the operation of the ADF 12, the scanner section 16 and the printer section 17 in response to the operation of the operation panel 13. The RAM 104 temporarily stores control data and is used for arithmetic operations at the time of control.

The operation panel 13 includes the plural keys 14 and the display section 15 used also as a touch panel, and can give various instructions for image formation. For example, the instruction of the number of copies is performed using the keys 14, and the instructions of sheet size, sheet type, stapling, punching and the like are performed by operating the touch panel of the display section 15.

A finisher control section 201 controls the operation of the finisher 20. The finisher control section 201 is connected to the main control section 101, and communicates information with the main control section 101. The MFP 10 and the finisher 20 operate in cooperation with each other. The finisher control section 201 performs the control of position of the stapler 23, execution of stapling, conveyance of the sheet S to the stapler 23, discharge of the sheet bundle after stapling, and the like.

For example, when a power button among the plural keys 14 is pressed and the power is turned on, the finisher control section 201 applies power to the electromagnets 65A and 65B to attract the magnetic members 63A and 63B, and the magnetic members 63A and 63B and the link plates 62A and 62B provide a taper-shaped expansion.

As described above, in this embodiment, when the MFP 10 and the finisher 20 are connected to each other, even if there is a step on the placement surface, the height position of the castor 53 is changed by contraction or extension of the spring 55. Thus, the height of the sheet discharge port of the sheet discharge roller 19 becomes equal to the height of the sheet feed port of the inlet roller 24, and the step can be absorbed. Besides, when the guide mechanism 60 is provided, the sheet S discharged from the MFP 10 can be fed without collision against the finisher 20.

Further, not limited to the above described-embodiment, and can be variously modified. For example, although the description is made to the example in which the stapler is provided in the finisher 20, a folding unit to fold a sheet bundle may be provided. Besides, a puncher to form a punch hole in a sheet may be provided.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. Indeed, the novel apparatus and methods described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the apparatus and methods described herein may be made without departing from the spirit of the invention. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the invention. 

1. A sheet processing apparatus for guiding a sheet from an image forming apparatus to a finishing apparatus, comprising: a support leg provided on an end bottom of the finishing apparatus at a side of the image forming apparatus; a spring member to support the support leg and extendable in a height direction; a sheet feed port which is formed in the finishing apparatus to be opposite to a sheet discharge port of the image forming apparatus and has a width wider than a width of the sheet discharge port in the height direction; sheet discharge guides which are arranged to be opposite to each other at an exit of the sheet discharge port and sandwich a conveyance path of the sheet in the image forming apparatus; sheet feed guides which are arranged to be opposite to each other at an inlet of the sheet feed port and sandwich a conveyance path of the sheet in the finishing apparatus; electromagnets provided at ends of the sheet feed guides at a side of the sheet feed port; magnetic members which are rotatably provided to ends of the sheet discharge guides at a side of the sheet discharge port and are attracted by the electromagnets; and a control section which drives the electromagnets in a state where the image forming apparatus is connected to the finishing apparatus, and causes the electromagnets to attract the magnetic members to provide a taper-shaped expansion.
 2. The apparatus of claim 1, wherein the support leg is a castor provided on the bottom of the finishing apparatus, and the castor is supported by the spring member, and if the image forming apparatus and the finishing apparatus are connected to each other, and if height positions of the sheet discharge port and the sheet feed port are different from each other, the spring member contracts or extends according to a difference between the height positions.
 3. The apparatus of claim 2, wherein a second castor is provided on the end bottom of the finishing apparatus at an opposite side to the image forming apparatus, and the second castor is supported by a second spring member.
 4. The apparatus of claim 1, further comprising: a projection provided on one of the image forming apparatus and the finishing apparatus as a height index at time of connection; and a reception port provided on the other, into which the projection is inserted.
 5. The apparatus of claim 1, wherein the electromagnets are excited if power is turned on in a state where the image forming apparatus and the finishing apparatus are connected to each other.
 6. The apparatus of claim 1, wherein if an interval between the sheet discharge guides is L1, and an interval between the sheet feed guides is L2, L1<L2 is established.
 7. The apparatus of claim 1, wherein the magnetic members are supported by link members provided at the ends of the sheet discharge guides at the side of the sheet discharge port, the link members and the magnetic members are parallel to the conveyance path of the sheet if power is not applied to the electromagnets, and the link members and the magnetic members are bent into a crank shape if power is applied to the electromagnets.
 8. A finishing apparatus for finishing a sheet discharged from an image forming apparatus, comprising: a support leg which is provided on an end bottom at a side of the image forming apparatus and supports a finishing section; a spring member to support the support leg and extendable in a height direction; a sheet feed port which is formed to be opposite to a sheet discharge port of the image forming apparatus and has a width wider than a width of the sheet discharge port in the height direction; sheet feed guides which are arranged to be opposite to each other at an inlet of the sheet feed port and sandwich a conveyance path of the sheet; electromagnets which are provided at ends of the sheet feed guides at a side of the sheet feed port and attract magnetic members rotatably provided at an exit of the sheet discharge port of the image forming apparatus; and a control section which drives the electromagnets in a state of connection to the image forming apparatus, and causes the electromagnets to attract the magnetic members to provide a taper-shaped expansion.
 9. The apparatus of claim 8, wherein the support leg is a castor provided on the bottom of the finishing apparatus, the castor is supported by the spring member, at time of connection to the image forming apparatus, if height positions of the sheet discharge port and the sheet feed port are different from each other, the spring member contracts or extends according to a difference between the height positions.
 10. The apparatus of claim 9, wherein a second castor is provided on the end bottom at an opposite side to the image forming apparatus, and the second castor is supported by a second spring member.
 11. The apparatus of claim 8, further comprising: a reception port into which a projection as an index of connection to the image forming apparatus is inserted.
 12. The apparatus of claim 8, wherein the electromagnets are excited if the finishing apparatus is connected to the image forming apparatus and power is turned on.
 13. The apparatus of claim 8, wherein if an interval between sheet discharge guides is L1, and an interval between the sheet feed guides is L2, L1<L2 is established.
 14. The apparatus of claim 8, wherein the magnetic members are supported by link members provided at ends of sheet discharge guides at a side of the sheet discharge port, the link members and the magnetic members are parallel to the conveyance path of the sheet if power is not applied to the electromagnets, and the link members and the magnetic members are bent into a crank shape if power is applied to the electromagnets.
 15. A sheet guide method for guiding a sheet from an image forming apparatus to a finishing apparatus, comprising: supporting a support leg provided on an end bottom of the finishing apparatus at a side of the image forming apparatus by a spring member extendable in a height direction; forming a sheet feed port in the finishing apparatus, which is opposite to a sheet discharge port of the image forming apparatus and has a width wider than a width of the sheet discharge port in the height direction; arranging sheet discharge guides which are opposite to each other at an exit of the sheet discharge port and sandwich a conveyance path of the sheet in the image forming apparatus; arranging sheet feed guides which are opposite to each other at an inlet of the sheet feed port and sandwich a conveyance path of the sheet in the finishing apparatus; providing electromagnets at ends of the sheet feed guides at a side of the sheet feed port, rotatably providing magnetic members to ends of the sheet discharge guides at a side of the sheet discharge port, and attracting the magnetic members by the electromagnets to provide a taper-shaped expansion.
 16. The method of claim 15, wherein the support leg is a castor provided on the bottom of the finishing apparatus, and the castor is supported by the spring member, and if the image forming apparatus and the finishing apparatus are connected to each other, and if height positions of the sheet discharge port and the sheet feed port are different from each other, the spring member contracts or extends according to a difference between the height positions.
 17. The method of claim 15, wherein a projection is provided on one of the image forming apparatus and the finishing apparatus as a height index at time of connection, and the projection is inserted into a reception port provided on the other.
 18. The method of claim 15, wherein the electromagnets are excited if power is turned on in a state where the image forming apparatus and the finishing apparatus are connected to each other.
 19. The method of claim 15, wherein if an interval between the sheet discharge guides is L1, and an interval between the sheet feed guides is L2, L1<L2 is established.
 20. The method of claim 15, wherein the magnetic members are supported by link members provided at the ends of the sheet discharge guides at the side of the sheet discharge port, the link members and the magnetic members are parallel to the conveyance path of the sheet if power is not applied to the electromagnets, and the link members and the magnetic members are bent into a crank shape if power is applied to the electromagnets.
 21. A sheet processing apparatus for guiding a sheet from an image forming apparatus to a finishing apparatus, comprising: a sheet feed port which is formed in the finishing apparatus to be opposite to a sheet discharge port of the image forming apparatus and has a width wider than a width of the sheet discharge port in a height direction; sheet discharge guides which are arranged to be opposite to each other at an exit of the sheet discharge port and sandwich a conveyance path of the sheet in the image forming apparatus; sheet feed guides which are arranged to be opposite to each other at an inlet of the sheet feed port and sandwich a conveyance path of the sheet in the finishing apparatus; a castor provided on an end bottom of the finishing apparatus at a side of the image forming apparatus; and a spring member to support the castor and extendable in the height direction, if the image forming apparatus and the finishing apparatus are connected to each other, and if height positions of the sheet discharge port and the sheet feed port are different from each other, the spring member contracts or extends according to a difference between the height positions.
 22. The apparatus of claim 21, wherein a second castor is provided on the end bottom of the finishing apparatus at an opposite side to the image forming apparatus, and the second castor is supported by a second spring member.
 23. The apparatus of claim 21, further comprising: a projection provided on one of the image forming apparatus and the finishing apparatus as a height index at time of connection; and a reception port provided on the other, into which the projection is inserted. 